BCI2000: 2D Control

Getting Started Follow the Passive Stimulus Presentation Data Collection Tutorial on the wiki – However, when the tutorial tells you to run StimPresentation run IpsiHand_Cursor Task instead – Also when you load the parameters, load IpsiHand_LPR_CursorTask_CR instead

Getting Data Before pressing start, make sure that ‘cursor task’ (the gridded window in the upper-left corner) is visible To move the ball to the right move your right hand. – Be sure to not move your head, blink, swallow, or move other muscles – Move your hand in a way that takes effort (eg. Play an imaginary piano, touch individual fingers together…) To move the ball to the left do not move at all In between trials it’s ok to blink

Analyzing the Data Follow the directions in User Tutorial: Performing Offline EEG Analysis – After instructed to click the “add” button, navigate to data\[your initials]\[most recent data file] instead of the three files suggested by the tutorial – For Condition 1 enter states.TargetCode ==1 – For Condition 2 enter states.TargetCode ==2 – For Trial Change Condition enter Feedback ==1 – Set Label 1 to “Pause” and Label 2 to “Right hand” Looking at the correlation maps, you want to see a few brightly colored bands in the sections between 9 and 24 Hz, and channels 1-4 The greater the correlation the better! Keep practicing and try to get your correlations above 0.20 Repeat data collection and analysis steps multiple times until you feel like you have some 1D control over the ball.

Homework 1: Troubleshooting in BCI2000 Run the CursorTask batch file Load the parameters called CursorTask_WithErrors Fix the errors and press set Config If you still get errors, try again!

Homework 2: Adjusting the Linear Classifier Run the cursor task batch file and load the parameters IpsiHand_LPR_CursorTask_CR Change the Linear Classifier so that you have 2D control (add electrodes mapping to output channel 2) – Output channel 2 can be different frequencies or different electrodes than output channel 1. – Change it up until you have at least a little bit of control over the ball – If you have complete control over the ball, you achieved the goal of the project!

Homework 3: Improving 2D Control Open a data set in matlab using the command like: [signal states parameters] = load_bcidat('C:\Users\Colleen\Dropbox\IpsiHand\BCI200 0\data\CR001\CRS001R04.dat'); – Except adjust the path so that MatLab loads your data file The variable “signal” should have 14 columns for the 14 electrodes – Create a new matrix made up of the electrodes from the signal that you care about

Improving 2D Control continued Run the command: [coeff,score] = princomp(signal_new); Look at the coeff matrix – The first column is the best weights for each electrode in the 1 st dimension and the second column is the best weights in the 2 nd dimension Go back to the linear classifier and try the new weights and see if CursorTask becomes easier – Repeat the directions from the slide “Analyzing the Data”

Solution Homework 1 Make the spatial filter a 4x4 identity matrix Repeat the first number for NormalizerOffsets, NormalizerGains, and Adaptation Add a high pass filter Change the SourceChOffset to fourteen zeros Change the SourceChGain to fourteen ones

Possible Solution Homework 2 Input ChannelInput element (bin) Ouput ChannelWeight 1112Hz Hz Hz Hz Hz Hz Hz Hz